Concentrated Walnut/Alkyd Medium thins the color, accelerates drying, enhances adhesion between layers and increases surface sheen and flexibility while remaining essentially non-yellowing. Ideally suited for alla-prima and glaze applications. Walnut/Alkyd Medium is certified nontoxic. M. Graham's Walnut/Alkyd Medium is designed to augment the special nature of M. Graham color but is also completely compatible with other artists' oil colors and mediums.